ENS 57422
ENS Event | |
|---|---|
14:02 Oct 10, 2024 | |
| Title | Secondary Containment Boundary Inoperable |
| Event Description | The following information was provided by the licensee via phone and email:
At 0902 EST, on 10/10/2024, with Millstone Unit 3 in mode 1 at 100 percent power, it was discovered that the secondary containment boundary was inoperable when the latch that secured a hatch that was part of the secondary containment boundary was not functional. The latch was repaired by 1115, on 10/10/2024, and the secondary containment boundary was declared operable at 1200, on 10/10/2024. The initial assessment of reportability concluded that an immediate report was not required. However, upon additional review, it has been determined that because the secondary containment boundary is a single-train system that performs a safety function, an 8-hour report was required in accordance with 10 CFR 50. 72 (b)(3)(v)(C) and (D). This report should have been made on 10/10/2024 and is late. There has been no impact to Unit 2, and Unit 3 continues to operate in mode 1 at 100 percent power. There is no impact on the health and safety of the public or plant personnel. The NRC Resident Inspector has been notified. |
| Where | |
|---|---|
Millstone  Connecticut (NRC Region 1) | |
| Reporting | |
| 10 CFR 50.72(b)(3)(v)(C), Loss of Safety Function - Release of Radioactive Material 10 CFR 50.72(b)(3)(v)(D), Loss of Safety Function - Mitigate the Consequences of an Accident | |
| Time - Person (Reporting Time:+814.6 h33.942 days <br />4.849 weeks <br />1.116 months <br />) | |
| Opened: | Robert Mello 13:38 Nov 13, 2024 |
| NRC Officer: | Tenisha Meadows |
| Last Updated: | Nov 13, 2024 |
| 57422 - NRC Website
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Unit 3 | |
|---|---|
| Reactor critical | Critical |
| Scram | No |
| Before | Power Operation (100 %) |
| After | Power Operation (100 %) |